stories, president obama says the u.s. will stand shoulder to shoulder with its south korean ally but at which point would a north korean attack provoke the u.s. military to step in. you see that video, that's what happened this time yesterday. the communist regime says it started firing on a small island after military exercises with seven -- after military exercises with 70,000 troops began. u.s. troops are on alert in the event of a strike. twenty-eight thousand soldiers are located in the de militarized zone in the buffer zone between the north and south. stephen yates was department ste stabt for security affairs from 2001-2005 and also president of the d.c. federal advisory. good morning to you. >> good morning. bill: simple question, simple point: what does north korea want out of this, why would it act? >> fortunately or unfortunately, very few of us have a clear idea of the mind of the dictator in the north. there is a well practiced